Stroke is a major public health problem in the United States, with an estimated 800,000 strokes each year and an estimated 7 million stroke survivors. It is the third leading cause of death in women and the fifth leading cause in men. Twenty percent of stroke survivors require institutional care after 3 months and 15%-30% are permanently disabled. Stroke in adults is strongly age dependent. Because the United States population is aging, the population at risk for stroke will increase over the coming decades, and women will outnumber men in terms of stroke events. Another important shift in the US demographics is the increase of women of color, projected to increase from 36 percent to 53 percent of the total US female population. Improving stroke surveillance to fill important knowledge gaps in the burden of stroke for understudied, underrepresented, and underreported subgroups of women is critical to identify strategies to lessen the burden of stroke for women. This administrative supplement will build upon the Disparities in Patterns of Recurrent Stroke in the Elderly parent R01 grant to assess stroke rates and outcomes for fee-for-service and Medicare Advantage beneficiaries. Medicare administrative data will be used to achieve the following specific aims: 1) To describe patterns in stroke hospitalizations and outcomes for women in understudied racial/ethnic minority groups and geographic regions among elderly Medicare beneficiaries; and 2) To describe patterns of stroke rates and outcomes according to dual-eligible Medicare-Medicaid status and geographic region. Our proposed study will address research priorities identified by the NIH Strategic Plan for Women?s Health Research to develop information systems for collecting, sharing, and comparing clinical data for diseases and conditions of women as well as to examine health disparities among women stemming from differences in race/ethnicity and socioeconomic status. The study also addresses priorities identified by the National Institute on Aging, the Institute of Medicine, and National Institute of Neurological Disorders and Stroke to develop surveillance systems to understand the continuum of disease prevention, progression, treatment, and outcomes, particularly for vulnerable populations. Clinical practice, public policy, and reimbursement decisions are increasingly informed by administrative datasets. This study will be the most comprehensive and rigorous investigation to date aimed at describing stroke rates and outcomes among women from understudied, underrepresented, and underreported populations, including Blacks/African Americans, Hispanics/Latinos, American Indians/Alaska Natives, Asian Americans, and Native Hawaiians and other Pacific Islanders. The study will also examine the stroke rates and outcomes among elderly Medicare-Medicaid beneficiaries, one of the most socioeconomically vulnerable populations in the US healthcare system. Such information is needed to inform the clinical management of women and underserved subgroups of patients with stroke.